unit md5_unit;

interface

uses
   Windows, SysUtils;
Type
   TMD5 = Array [0..15] of byte;

function MD5(s: string): string;
function MD5_arr(s: string): TMD5;

implementation
//==============================================================================
function Int2Hex( Value : DWord; Digits : Integer ) : String;
asm
        PUSH      0
        ADD       ESP, -0Ch

        PUSH      EBX
        PUSH      ECX

        LEA       EBX, [ESP+8+0Fh]  // EBX := @Buf[ 15 ]
        AND       EDX, $F

@@loop: DEC       EBX
        DEC       EDX

        PUSH      EAX
        {$IFDEF PARANOIA}
        DB $24, $0F
        {$ELSE}
        AND       AL, 0Fh
        {$ENDIF}
        {$IFDEF PARANOIA}
        DB $3C, 9
        {$ELSE}
        CMP       AL, 9
        {$ENDIF}
        JA        @@10
        {$IFDEF PARANOIA}
        DB $04, 30h-41h+0Ah
        {$ELSE}
        ADD       AL,30h-41h+0Ah
        {$ENDIF}
@@10:
        {$IFDEF PARANOIA}
        DB $04, 41h-0Ah
        {$ELSE}
        ADD       AL,41h-0Ah
        {$ENDIF}
        MOV       byte ptr [EBX], AL
        POP       EAX
        SHR       EAX, 4

        JNZ       @@loop

        TEST      EDX, EDX
        JG        @@loop

        POP       EAX      // EAX = @Result
        MOV       EDX, EBX // EDX = @resulting string
        CALL      System.@LStrFromPChar

        POP       EBX
        ADD       ESP, 10h

end;                     
//==============================================================================
function MD5(s: string): string;
var
   a : TMD5;
   i : integer;
   LenHi, LenLo: longword;
   Index: DWord;
   HashBuffer  : array[0..63] of byte;
   CurrentHash : array[0..3] of DWord;

   procedure Burn;
   begin
      LenHi:= 0; LenLo:= 0;
      Index:= 0;
      FillChar(HashBuffer,Sizeof(HashBuffer),0);
      FillChar(CurrentHash,Sizeof(CurrentHash),0);
   end;

   procedure Init;
   begin
      Burn;
      CurrentHash[0]:= $67452301;
      CurrentHash[1]:= $efcdab89;
      CurrentHash[2]:= $98badcfe;
      CurrentHash[3]:= $10325476;
   end;

   function LRot32(a, b: longword): longword;
   begin
      Result:= (a shl b) or (a shr (32-b));
   end;

   procedure Compress;
   var
      Data : array[0..15] of dword;
      A, B, C, D: dword;
   begin
      Move(HashBuffer,Data,Sizeof(Data));
      A:= CurrentHash[0];
      B:= CurrentHash[1];
      C:= CurrentHash[2];
      D:= CurrentHash[3];

      A:= B + LRot32(A + (D xor (B and (C xor D))) + Data[ 0] + $d76aa478,7);
      D:= A + LRot32(D + (C xor (A and (B xor C))) + Data[ 1] + $e8c7b756,12);
      C:= D + LRot32(C + (B xor (D and (A xor B))) + Data[ 2] + $242070db,17);
      B:= C + LRot32(B + (A xor (C and (D xor A))) + Data[ 3] + $c1bdceee,22);
      A:= B + LRot32(A + (D xor (B and (C xor D))) + Data[ 4] + $f57c0faf,7);
      D:= A + LRot32(D + (C xor (A and (B xor C))) + Data[ 5] + $4787c62a,12);
      C:= D + LRot32(C + (B xor (D and (A xor B))) + Data[ 6] + $a8304613,17);
      B:= C + LRot32(B + (A xor (C and (D xor A))) + Data[ 7] + $fd469501,22);
      A:= B + LRot32(A + (D xor (B and (C xor D))) + Data[ 8] + $698098d8,7);
      D:= A + LRot32(D + (C xor (A and (B xor C))) + Data[ 9] + $8b44f7af,12);
      C:= D + LRot32(C + (B xor (D and (A xor B))) + Data[10] + $ffff5bb1,17);
      B:= C + LRot32(B + (A xor (C and (D xor A))) + Data[11] + $895cd7be,22);
      A:= B + LRot32(A + (D xor (B and (C xor D))) + Data[12] + $6b901122,7);
      D:= A + LRot32(D + (C xor (A and (B xor C))) + Data[13] + $fd987193,12);
      C:= D + LRot32(C + (B xor (D and (A xor B))) + Data[14] + $a679438e,17);
      B:= C + LRot32(B + (A xor (C and (D xor A))) + Data[15] + $49b40821,22);
    
      A:= B + LRot32(A + (C xor (D and (B xor C))) + Data[ 1] + $f61e2562,5);
      D:= A + LRot32(D + (B xor (C and (A xor B))) + Data[ 6] + $c040b340,9);
      C:= D + LRot32(C + (A xor (B and (D xor A))) + Data[11] + $265e5a51,14);
      B:= C + LRot32(B + (D xor (A and (C xor D))) + Data[ 0] + $e9b6c7aa,20);
      A:= B + LRot32(A + (C xor (D and (B xor C))) + Data[ 5] + $d62f105d,5);
      D:= A + LRot32(D + (B xor (C and (A xor B))) + Data[10] + $02441453,9);
      C:= D + LRot32(C + (A xor (B and (D xor A))) + Data[15] + $d8a1e681,14);
      B:= C + LRot32(B + (D xor (A and (C xor D))) + Data[ 4] + $e7d3fbc8,20);
      A:= B + LRot32(A + (C xor (D and (B xor C))) + Data[ 9] + $21e1cde6,5);
      D:= A + LRot32(D + (B xor (C and (A xor B))) + Data[14] + $c33707d6,9);
      C:= D + LRot32(C + (A xor (B and (D xor A))) + Data[ 3] + $f4d50d87,14);
      B:= C + LRot32(B + (D xor (A and (C xor D))) + Data[ 8] + $455a14ed,20);
      A:= B + LRot32(A + (C xor (D and (B xor C))) + Data[13] + $a9e3e905,5);
      D:= A + LRot32(D + (B xor (C and (A xor B))) + Data[ 2] + $fcefa3f8,9);
      C:= D + LRot32(C + (A xor (B and (D xor A))) + Data[ 7] + $676f02d9,14);
      B:= C + LRot32(B + (D xor (A and (C xor D))) + Data[12] + $8d2a4c8a,20);
    
      A:= B + LRot32(A + (B xor C xor D) + Data[ 5] + $fffa3942,4);
      D:= A + LRot32(D + (A xor B xor C) + Data[ 8] + $8771f681,11);
      C:= D + LRot32(C + (D xor A xor B) + Data[11] + $6d9d6122,16);
      B:= C + LRot32(B + (C xor D xor A) + Data[14] + $fde5380c,23);
      A:= B + LRot32(A + (B xor C xor D) + Data[ 1] + $a4beea44,4);
      D:= A + LRot32(D + (A xor B xor C) + Data[ 4] + $4bdecfa9,11);
      C:= D + LRot32(C + (D xor A xor B) + Data[ 7] + $f6bb4b60,16);
      B:= C + LRot32(B + (C xor D xor A) + Data[10] + $bebfbc70,23);
      A:= B + LRot32(A + (B xor C xor D) + Data[13] + $289b7ec6,4);
      D:= A + LRot32(D + (A xor B xor C) + Data[ 0] + $eaa127fa,11);
      C:= D + LRot32(C + (D xor A xor B) + Data[ 3] + $d4ef3085,16);
      B:= C + LRot32(B + (C xor D xor A) + Data[ 6] + $04881d05,23);
      A:= B + LRot32(A + (B xor C xor D) + Data[ 9] + $d9d4d039,4);
      D:= A + LRot32(D + (A xor B xor C) + Data[12] + $e6db99e5,11);
      C:= D + LRot32(C + (D xor A xor B) + Data[15] + $1fa27cf8,16);
      B:= C + LRot32(B + (C xor D xor A) + Data[ 2] + $c4ac5665,23);
    
      A:= B + LRot32(A + (C xor (B or (not D))) + Data[ 0] + $f4292244,6);
      D:= A + LRot32(D + (B xor (A or (not C))) + Data[ 7] + $432aff97,10);
      C:= D + LRot32(C + (A xor (D or (not B))) + Data[14] + $ab9423a7,15);
      B:= C + LRot32(B + (D xor (C or (not A))) + Data[ 5] + $fc93a039,21);
      A:= B + LRot32(A + (C xor (B or (not D))) + Data[12] + $655b59c3,6);
      D:= A + LRot32(D + (B xor (A or (not C))) + Data[ 3] + $8f0ccc92,10);
      C:= D + LRot32(C + (A xor (D or (not B))) + Data[10] + $ffeff47d,15);
      B:= C + LRot32(B + (D xor (C or (not A))) + Data[ 1] + $85845dd1,21);
      A:= B + LRot32(A + (C xor (B or (not D))) + Data[ 8] + $6fa87e4f,6);
      D:= A + LRot32(D + (B xor (A or (not C))) + Data[15] + $fe2ce6e0,10);
      C:= D + LRot32(C + (A xor (D or (not B))) + Data[ 6] + $a3014314,15);
      B:= C + LRot32(B + (D xor (C or (not A))) + Data[13] + $4e0811a1,21);
      A:= B + LRot32(A + (C xor (B or (not D))) + Data[ 4] + $f7537e82,6);
      D:= A + LRot32(D + (B xor (A or (not C))) + Data[11] + $bd3af235,10);
      C:= D + LRot32(C + (A xor (D or (not B))) + Data[ 2] + $2ad7d2bb,15);
      B:= C + LRot32(B + (D xor (C or (not A))) + Data[ 9] + $eb86d391,21);
    
      Inc(CurrentHash[0],A);
      Inc(CurrentHash[1],B);
      Inc(CurrentHash[2],C);
      Inc(CurrentHash[3],D);
      Index:= 0;
      FillChar(HashBuffer,Sizeof(HashBuffer),0);
   end;

procedure Update(const Buffer; Size: longword);
var
   PBuf: ^byte;
begin
   Inc(LenHi,Size shr 29);
   Inc(LenLo,Size*8);
   if LenLo < (Size*8) then  Inc(LenHi);
   PBuf:= @Buffer;
   while Size> 0 do
   begin
      if (Sizeof(HashBuffer)-Index)<= DWord(Size) then
      begin
         Move(PBuf^,HashBuffer[Index],Sizeof(HashBuffer)-Index);
         Dec(Size,Sizeof(HashBuffer)-Index);
         Inc(PBuf,Sizeof(HashBuffer)-Index);
         Compress;
       end else
       begin
          Move(PBuf^,HashBuffer[Index],Size);
          Inc(Index,Size);
          Size:= 0;
       end;
   end;
end;

procedure Final(var Digest);
begin
  HashBuffer[Index] := $80;
  if Index>= 56 then Compress;
  PDWord(@HashBuffer[56])^ := LenLo;
  PDWord(@HashBuffer[60])^ := LenHi;
  Compress;
  Move(CurrentHash, Digest, Sizeof(CurrentHash));
  Burn;
end;

begin
   Init;
   Update(s[1], Length(s));
   Final(a);
   result := '';
   for i := 0 to 15 do result := result + Int2Hex(a[i], 2);
   Burn;
end;
//==============================================================================
function MD5_arr(s: string): TMD5;
var
   a : TMD5;
   LenHi, LenLo: longword;
   Index: DWord;
   HashBuffer  : array[0..63] of byte;
   CurrentHash : array[0..3] of DWord;

   procedure Burn;
   begin
      LenHi:= 0; LenLo:= 0;
      Index:= 0;
      FillChar(HashBuffer,Sizeof(HashBuffer),0);
      FillChar(CurrentHash,Sizeof(CurrentHash),0);
   end;

   procedure Init;
   begin
      Burn;
      CurrentHash[0]:= $67452301;
      CurrentHash[1]:= $efcdab89;
      CurrentHash[2]:= $98badcfe;
      CurrentHash[3]:= $10325476;
   end;

   function LRot32(a, b: longword): longword;
   begin
      Result:= (a shl b) or (a shr (32-b));
   end;

   procedure Compress;
   var
      Data : array[0..15] of dword;
      A, B, C, D: dword;
   begin
      Move(HashBuffer,Data,Sizeof(Data));
      A:= CurrentHash[0];
      B:= CurrentHash[1];
      C:= CurrentHash[2];
      D:= CurrentHash[3];

      A:= B + LRot32(A + (D xor (B and (C xor D))) + Data[ 0] + $d76aa478,7);
      D:= A + LRot32(D + (C xor (A and (B xor C))) + Data[ 1] + $e8c7b756,12);
      C:= D + LRot32(C + (B xor (D and (A xor B))) + Data[ 2] + $242070db,17);
      B:= C + LRot32(B + (A xor (C and (D xor A))) + Data[ 3] + $c1bdceee,22);
      A:= B + LRot32(A + (D xor (B and (C xor D))) + Data[ 4] + $f57c0faf,7);
      D:= A + LRot32(D + (C xor (A and (B xor C))) + Data[ 5] + $4787c62a,12);
      C:= D + LRot32(C + (B xor (D and (A xor B))) + Data[ 6] + $a8304613,17);
      B:= C + LRot32(B + (A xor (C and (D xor A))) + Data[ 7] + $fd469501,22);
      A:= B + LRot32(A + (D xor (B and (C xor D))) + Data[ 8] + $698098d8,7);
      D:= A + LRot32(D + (C xor (A and (B xor C))) + Data[ 9] + $8b44f7af,12);
      C:= D + LRot32(C + (B xor (D and (A xor B))) + Data[10] + $ffff5bb1,17);
      B:= C + LRot32(B + (A xor (C and (D xor A))) + Data[11] + $895cd7be,22);
      A:= B + LRot32(A + (D xor (B and (C xor D))) + Data[12] + $6b901122,7);
      D:= A + LRot32(D + (C xor (A and (B xor C))) + Data[13] + $fd987193,12);
      C:= D + LRot32(C + (B xor (D and (A xor B))) + Data[14] + $a679438e,17);
      B:= C + LRot32(B + (A xor (C and (D xor A))) + Data[15] + $49b40821,22);
    
      A:= B + LRot32(A + (C xor (D and (B xor C))) + Data[ 1] + $f61e2562,5);
      D:= A + LRot32(D + (B xor (C and (A xor B))) + Data[ 6] + $c040b340,9);
      C:= D + LRot32(C + (A xor (B and (D xor A))) + Data[11] + $265e5a51,14);
      B:= C + LRot32(B + (D xor (A and (C xor D))) + Data[ 0] + $e9b6c7aa,20);
      A:= B + LRot32(A + (C xor (D and (B xor C))) + Data[ 5] + $d62f105d,5);
      D:= A + LRot32(D + (B xor (C and (A xor B))) + Data[10] + $02441453,9);
      C:= D + LRot32(C + (A xor (B and (D xor A))) + Data[15] + $d8a1e681,14);
      B:= C + LRot32(B + (D xor (A and (C xor D))) + Data[ 4] + $e7d3fbc8,20);
      A:= B + LRot32(A + (C xor (D and (B xor C))) + Data[ 9] + $21e1cde6,5);
      D:= A + LRot32(D + (B xor (C and (A xor B))) + Data[14] + $c33707d6,9);
      C:= D + LRot32(C + (A xor (B and (D xor A))) + Data[ 3] + $f4d50d87,14);
      B:= C + LRot32(B + (D xor (A and (C xor D))) + Data[ 8] + $455a14ed,20);
      A:= B + LRot32(A + (C xor (D and (B xor C))) + Data[13] + $a9e3e905,5);
      D:= A + LRot32(D + (B xor (C and (A xor B))) + Data[ 2] + $fcefa3f8,9);
      C:= D + LRot32(C + (A xor (B and (D xor A))) + Data[ 7] + $676f02d9,14);
      B:= C + LRot32(B + (D xor (A and (C xor D))) + Data[12] + $8d2a4c8a,20);
    
      A:= B + LRot32(A + (B xor C xor D) + Data[ 5] + $fffa3942,4);
      D:= A + LRot32(D + (A xor B xor C) + Data[ 8] + $8771f681,11);
      C:= D + LRot32(C + (D xor A xor B) + Data[11] + $6d9d6122,16);
      B:= C + LRot32(B + (C xor D xor A) + Data[14] + $fde5380c,23);
      A:= B + LRot32(A + (B xor C xor D) + Data[ 1] + $a4beea44,4);
      D:= A + LRot32(D + (A xor B xor C) + Data[ 4] + $4bdecfa9,11);
      C:= D + LRot32(C + (D xor A xor B) + Data[ 7] + $f6bb4b60,16);
      B:= C + LRot32(B + (C xor D xor A) + Data[10] + $bebfbc70,23);
      A:= B + LRot32(A + (B xor C xor D) + Data[13] + $289b7ec6,4);
      D:= A + LRot32(D + (A xor B xor C) + Data[ 0] + $eaa127fa,11);
      C:= D + LRot32(C + (D xor A xor B) + Data[ 3] + $d4ef3085,16);
      B:= C + LRot32(B + (C xor D xor A) + Data[ 6] + $04881d05,23);
      A:= B + LRot32(A + (B xor C xor D) + Data[ 9] + $d9d4d039,4);
      D:= A + LRot32(D + (A xor B xor C) + Data[12] + $e6db99e5,11);
      C:= D + LRot32(C + (D xor A xor B) + Data[15] + $1fa27cf8,16);
      B:= C + LRot32(B + (C xor D xor A) + Data[ 2] + $c4ac5665,23);
    
      A:= B + LRot32(A + (C xor (B or (not D))) + Data[ 0] + $f4292244,6);
      D:= A + LRot32(D + (B xor (A or (not C))) + Data[ 7] + $432aff97,10);
      C:= D + LRot32(C + (A xor (D or (not B))) + Data[14] + $ab9423a7,15);
      B:= C + LRot32(B + (D xor (C or (not A))) + Data[ 5] + $fc93a039,21);
      A:= B + LRot32(A + (C xor (B or (not D))) + Data[12] + $655b59c3,6);
      D:= A + LRot32(D + (B xor (A or (not C))) + Data[ 3] + $8f0ccc92,10);
      C:= D + LRot32(C + (A xor (D or (not B))) + Data[10] + $ffeff47d,15);
      B:= C + LRot32(B + (D xor (C or (not A))) + Data[ 1] + $85845dd1,21);
      A:= B + LRot32(A + (C xor (B or (not D))) + Data[ 8] + $6fa87e4f,6);
      D:= A + LRot32(D + (B xor (A or (not C))) + Data[15] + $fe2ce6e0,10);
      C:= D + LRot32(C + (A xor (D or (not B))) + Data[ 6] + $a3014314,15);
      B:= C + LRot32(B + (D xor (C or (not A))) + Data[13] + $4e0811a1,21);
      A:= B + LRot32(A + (C xor (B or (not D))) + Data[ 4] + $f7537e82,6);
      D:= A + LRot32(D + (B xor (A or (not C))) + Data[11] + $bd3af235,10);
      C:= D + LRot32(C + (A xor (D or (not B))) + Data[ 2] + $2ad7d2bb,15);
      B:= C + LRot32(B + (D xor (C or (not A))) + Data[ 9] + $eb86d391,21);
    
      Inc(CurrentHash[0],A);
      Inc(CurrentHash[1],B);
      Inc(CurrentHash[2],C);
      Inc(CurrentHash[3],D);
      Index:= 0;
      FillChar(HashBuffer,Sizeof(HashBuffer),0);
   end;

procedure Update(const Buffer; Size: longword);
var
   PBuf: ^byte;
begin
   Inc(LenHi,Size shr 29);
   Inc(LenLo,Size*8);
   if LenLo < (Size*8) then  Inc(LenHi);
   PBuf:= @Buffer;
   while Size> 0 do
   begin
      if (Sizeof(HashBuffer)-Index)<= DWord(Size) then
      begin
         Move(PBuf^,HashBuffer[Index],Sizeof(HashBuffer)-Index);
         Dec(Size,Sizeof(HashBuffer)-Index);
         Inc(PBuf,Sizeof(HashBuffer)-Index);
         Compress;
       end else
       begin
          Move(PBuf^,HashBuffer[Index],Size);
          Inc(Index,Size);
          Size:= 0;
       end;
   end;
end;

procedure Final(var Digest);
begin
   HashBuffer[Index] := $80;
   if Index >= 56 then Compress;
   PDWord(@HashBuffer[56])^ := LenLo;
   PDWord(@HashBuffer[60])^ := LenHi;
   Compress;
   Move(CurrentHash, Digest, Sizeof(CurrentHash));
   Burn;
end;

begin
   Init;
   Update(s[1], Length(s));
   Final(a);
   result := a;
   Burn;
end;

end.












